As discussed in U.S. Pat. No. 5,675,104, minefields represent a major danger to equipment and personnel during military action. In order to permit the passage of tanks and other heavy vehicles, there is a necessity to be able to quickly breach or clear a lane through a minefield so one can bring vehicles through the minefield safely.
In the past, the traditional way to clear a lane through a minefield was to use large mechanized equipment such as plows or bulldozers to bulldoze or plow any buried mines out of the way.
In terms of the plowing technique, special blades were provided in front of the vehicle so that if mines blew up, they damaged the plow but did not damage the entire vehicle.
A second way of clearing a minefield was to deploy big-chain beaters called flails to beat the ground. The equipment necessary to deploy such beating equipment included apparatus to pick up the chains on a rotating drum and then beat the ground or pulverize the ground to set off any mines.
Typically, the chains were mounted on large vehicles out in front of the vehicle so that when the mine blew up, the mine would blow up in front of the vehicle but not directly under it.
A further approach that has been applied has been to mount a heavy roller on the front of a tank and to put a considerable load on the roller. When the roller was rolled over a landmine it was designed to set off any mines in front of the tank due to the loading of the roller. In the process the roller was destroyed. Sometimes the roller was ineffective if the pressure on the ground was insufficient to set off the mine.
Another method for clearing a minefield was to utilize individual rocket-launched explosives deployed and detonated over a minefield. A further system called the Giant Viper or MICLIC used linear bulk explosives pulled across a minefield by a rocket. In one such system a rocket motor was attached to one end of the charge and towed the charge across the minefield, whereupon it was detonated to provide overpressure waves to detonate or damage the mines so that one had a clear lane through the minefield.
It is noted that the explosive utilized in these cases was a bulk explosive and not a shaped charge, with the bulk explosive attacking the mine fuse, as opposed to the mine.
While these techniques may have been successful in the past, modern fusing technology results in landmine designs in which the fuses for the mines require sustained pressure in order to set them off. The result is that the explosive overpressure from bulk explosives will not set them off because of its transient impulse.
Thus, with respect to the above mechanized techniques, one had to deploy massive, heavy equipment that one had to bring along on the mission. The use of the heavy equipment meant that mine clearing was a relatively slow process. For instance, it could take half an hour to clear a lane of mines, with the problem being particularly difficult when exposed to enemy fire.
Moreover, with respect to rollers, tanks with plow blades and other mechanized breaching equipment, while the equipment might be effective to detonate a mine, the result is disabled equipment within the lane that one is seeking to clear.
It will be appreciated that the mines to be cleared by the technique of the subject invention are antitank mines as opposed to anti-personnel mines. The anti-personnel mines are smaller and fairly easy to trip and are designed to kill or at least maim a person. These mines may utilize either a pound or a couple of pounds of explosive.
On the other hand, antitank mines are designed to be detonated when a large vehicle or tank is driving over them. For instance, antitank mines are not designed to go off when a small vehicle goes over the mine. Also they typically have 10 to 25 pounds of explosives.
Antitank mines are deployed either at surface level on top of the ground or between four to six inches below the surface of the ground, with some being buried even deeper, for instance, to the depth of a foot.
In more recent times, the so-called Mongoose project was developed, which involved a rocket-deployed net or array of shaped-charge munitions. As described in U.S. Pat. No. 5,675,104 as well as U.S. Pat. Nos. 5,614,692 and 5,524,524, the Mongoose involved a rocket-deployed net or array full of shaped-charge munitions. The net is towed onto the minefield by the rocket such that the net settles down over the earth, with the shaped charge munitions pointing downwardly into the earth. Rather than relying on bulk explosives where one is relying on a pressure pulse to set off the mine fuse, the shaped charge attacks the mine explosive with a shaped charge jet that impacts the mine. These shaped charges deliver enough kinetic energy to the mine explosive to cause the mines to detonate rather than relying on the mine's fuse.
In one embodiment of the Mongoose system, a large number of shaped-charge munitions are carried in a net, with all pointed into the ground such that when the munitions are all simultaneously detonated, it is equivalent to having bullets spaced at regular intervals piercing the ground. If they hit a mine, then they have enough energy to cause the mine to detonate.
This type of mine-breaching system requires a vehicle-mounted launcher that launches the rocket such that it lands with the net being between 50 and 135 meters in length and at a safe standoff distance in front of the launching vehicle. The net is deployed in mid-air so that it stretches out laterally along its entire length to create a lane for follow-on vehicles.
What will be appreciated with the rocket-deployed array is that the net needs to be tight and oriented properly such that all of the individual munitions are pointed straight down into the ground and are spaced properly.
This is a point attack system in which a large number of shaped-charge munitions are each attacking a different point. Moreover, the design is such that the spacing does not leave any mines that fall in between the munitions.
The problem with all of the aforementioned systems is the weight of the system, the cost of the system and the its effectiveness.
Also important is the complexity of the system and, with respect to the net, one must provide a net having structural capability to handle the loads and the rocket motor.